been produced on a laboratory and 

 semicommercial basis from combina- 

 tions of sulphite and ground-wood 

 pulps, such as are normally used by 

 the industry in manufacturing this 

 type of paper. 



| Since production of newsprint by 

 "his method requires specially selected 

 wood, which is an added cost and leaves 

 much heart-bearing cull wood to be 

 disposed of, the Laboratory has devel- 

 oped the use of semibleached sulphate 

 pulp as a substitute for the sulphite, 

 and. has proved the effectiveness of this 

 procedure by extended tests. The 

 alkaline sulphate process readily re- 

 duces heartwood, does not require 

 light-colored wood, and practically elim- 

 inates the possibility of pitch diffi- 

 culties. The currently proposed news- 

 print developments in the South are in 

 practically all cases tending toward this 

 latter method of conversion. 



The Laboratory has not only pro- 

 duced newsprint from various com- 

 binations of pine but has also used 

 mixtures of pine with such southern 

 hardwoods as gum. These develop- 

 ments offer possibilities for use of the 

 southern hardwoods and for minimizing 

 pitch troubles should these arise in 

 mill operations. 



In the forests of the Pacific North- 

 west, the Nation has other great 

 supplies of actual and potential pulp- 

 woods. Enough Douglas fir is left on 

 the ground as logging waste each year 

 to duplicate almost our entire pulp 

 output from domestic sources — if 

 Douglas fir can be adapted to diversi- 

 fied pulp production. The Laboratory 

 is working to secure this result by 

 special modifications of the sulphate 

 and other processes. Experimental 

 papers of good quality and strength 

 have been obtained. Pulping experi- 



M-26380-F 



On the way to the paper machine the pulp, 



after bleaching, is further refined 



in the beater. 



ments also with western larch, white 

 fir, red cedar, Sitka spruce, and other 

 western species are returning a promis- 

 ing variety of book, writing, wrapping, 

 and newsprint papers. 



Improvement of 

 pulping processes 



As urgently needed as the extension 

 of pulping to new species is the pro- 

 gressive improvement of pulping opera- 

 tions, looking to the more efficient 

 utilization of woods of all species. 

 Studies of chemical pulping are carried 

 on constantly and are showing the way 

 to substantial increases of yields and 

 improvement of pulp quality. Appli- 

 cation of the findings is resulting in 

 more satisfactory and economical pro- 

 duction through a proper balance of 



31 



